C++/C header and source file definitions

Recently, when I tried to use Makefile to compile and link several .cpp files under Ubuntu, I found that irregular writing of header files and source files would cause error problems. Now I will record the definition specifications of C++/C header files and source files:

Requirements: Write main.cpp, myfunctions.h, myfunctions.cpp, and include the myfunctions.h header file in main.cpp to call the function implemented in myfunctions.cpp to print out Hello world!

myfunctions.h definition:

#ifndef MYFUNCTIONS_H
#define MYFUNCTIONS_H

void MyFunction(void);

#endif 

 myfunctions.cpp definition:

#include <stdio.h>
#include "myfunctions.h"
void MyFunction(void){
	printf("Hello world!\n");
	return ;
}

main.cpp definition: 

#include <stdio.h>
#include "myfunctions.h"

int main(){
	MyFunction();
	return 0;
}

It should be noted that to include header files in main.cpp, you need to use #include "myfunctions.h" but #include <myfunctions.h> cannot be used. The source file that implements the function must include the corresponding header file used.